# Measuring power consumption on Arduino off of DC supply

I am working on a project involving the Uno, and I would like to benchmark the power requirements of Arduino. I am using the external 9V supply option.

Specifically, the Uno will be in to states,`power-intensive` and `power-save`. In the first mode, I am doing some heavy processing tasks (RF and some sensors are the only external loads), and the Arduino typically runs `loop()` without any delays. In the second mode, `loop()` is execued about every 10-40 seconds.

I am interested in benchmarking how much power is consumed in both states (I need this to estimate the size of the battery required for the 9V supply).

Obviously, googling yielded me solutions that involved measuring current using chips in series with the supply (I probably can pull this off with a multimeter). What I am wondering is whether there exists an elegant solution for this, with (highly) accurate results (I would most likely quote the power values, so accuracy is a must for me)? Something I can dynamically measure on the Uno itself?

• If you're worried about power consumption then you need to move away from Arduino completely and work on a standalone solution with the bare MCU and a switching power supply. Dec 4, 2014 at 15:07
• I just need to benchmark for comparision. Can you please elaborate.
– xyz
Dec 4, 2014 at 15:11
• A multimeter will be fine for battery life expectancy. If you want more precision, you need something like a uCurrent and a oscilloscope that can calculate the area underneath the curve. But first, I'd try using a multimeter and a 5V supply (5v as to eliminate the power usage of the voltage regulator). Measure the current during processes, and during "sleep". Dec 4, 2014 at 17:17

What I am wondering is whether there exists an elegant solution for this, with (highly) accurate results (I would most likely quote the power values, so accuracy is a must for me)? Something I can dynamically measure on the Uno itself?

The Uno cannot measure its own power consumption. Indeed, a Uno which has a voltage regulator, power LED, and USB interface chip is not your ideal solution for low-power applications.